The overall objectives of this research project involve the isolation, chemical, structural and immunochemical characterization of tumor-derived glycoproteins at the cell surface and those elaborated into the culture medium which may play a role in cell-cell recognition phenomena and tumor antigenicity; and the elucidation of the mechanisms controlling modulation of glycoprotein expression. Emphasis will be given to murine ascites systems and human ovarian cancer. Glycoproteins will be isolated primarily by affinity chromatographic techniques using insolubilized lectins. Metabolically labeled (with glycoprotein presursors) radioactive glycoproteins will be used to provide an assay system for tumor-derived glycoproteins. Glycoproteins correlated with murine tumor attenuation as a result of in vitro growth will receive emphasis. Changes in activities of glycosyltransferases associated with glycoprotein changes will be studied using tumor-derived glycoproteins as acceptors.